OpenGL: Add libepoxy optional dependency

CMakeLists.txt

@@ -24,6 +24,7 @@ set(BUILD_STATIC OFF CACHE BOOL "Build a static library")
 set(BUILD_SHARED ON CACHE BOOL "Build a shared library")
 set(BUILD_GL ON CACHE STRING "Build with OpenGL")
 set(BUILD_GLES2 OFF CACHE STRING "Build with OpenGL|ES 2")
+set(USE_EPOXY ON CACHE STRING "Build with libepoxy")
 set(DISABLE_DEPS OFF CACHE BOOL "Build without dependencies")
 file(GLOB ARM_SRC ${CMAKE_SOURCE_DIR}/src/arm/*.c)
 file(GLOB GBA_SRC ${CMAKE_SOURCE_DIR}/src/gba/*.c)
@@ -284,6 +285,7 @@ find_feature(USE_ZLIB "ZLIB")
 find_feature(USE_PNG "PNG")
 find_feature(USE_LIBZIP "libzip")
 find_feature(USE_MAGICK "MagickWand")
+find_feature(USE_EPOXY "epoxy")
 
 # Features
 set(DEBUGGER_SRC ${CMAKE_SOURCE_DIR}/src/debugger/debugger.c ${CMAKE_SOURCE_DIR}/src/debugger/memory-debugger.c)
@@ -436,6 +438,15 @@ if (USE_LZMA)
 	list(APPEND FEATURES LZMA)
 endif()
 
+if(USE_EPOXY)
+	add_definitions(-DBUILD_GL -DBUILD_GLES2)
+	list(APPEND FEATURES EPOXY)
+	include_directories(AFTER ${EPOXY_INCLUDE_DIRS})
+	set(OPENGLES2_LIBRARY ${EPOXY_LIBRARIES})
+	set(CPACK_DEBIAN_PACKAGE_DEPENDS "${CPACK_DEBIAN_PACKAGE_DEPENDS},libepoxy0")
+endif()
+
+
 set(FEATURE_DEFINES)
 foreach(FEATURE IN LISTS FEATURES)
 	list(APPEND FEATURE_DEFINES "USE_${FEATURE}")

src/platform/opengl/gl.h

@@ -6,7 +6,9 @@
 #ifndef GL_H
 #define GL_H
 
-#ifdef __APPLE__
+#ifdef USE_EPOXY
+#include <epoxy/gl.h>
+#elif defined(__APPLE__)
 #include <OpenGL/gl.h>
 #else
 #include <GL/gl.h>

src/platform/opengl/gles2.h

@@ -6,12 +6,14 @@
 #ifndef GLES2_H
 #define GLES2_H
 
-#ifdef BUILD_GL
+#ifdef USE_EPOXY
+#include <epoxy/gl.h>
+#elif defined(BUILD_GL)
 #ifdef __APPLE__
 #include <OpenGL/gl3.h>
 #else
-#include <GL/gl.h>
 #define GL_GLEXT_PROTOTYPES
+#include <GL/gl.h>
 #include <GL/glext.h>
 #endif
 #else

src/platform/qt/CMakeLists.txt

@@ -48,7 +48,7 @@ endif()
 
 if(BUILD_GL)
 	list(APPEND PLATFORM_SRC ${CMAKE_SOURCE_DIR}/src/platform/opengl/gl.c)
-	if(NOT WIN32)
+	if(NOT WIN32 OR USE_EPOXY)
 		list(APPEND PLATFORM_SRC ${CMAKE_SOURCE_DIR}/src/platform/opengl/gles2.c)
 	endif()
 endif()

src/platform/qt/DisplayGL.cpp

@@ -14,8 +14,11 @@ extern "C" {
 #ifdef BUILD_GL
 #include "platform/opengl/gl.h"
 #endif
-#if !defined(_WIN32)
+#if !defined(_WIN32) || defined(USE_EPOXY)
 #include "platform/opengl/gles2.h"
+#ifdef _WIN32 
+#include <epoxy/wgl.h>
+#endif
 #endif
 }
 
@@ -151,11 +154,11 @@ PainterGL::PainterGL(QGLWidget* parent, QGLFormat::OpenGLVersionFlags glVersion)
 #ifdef BUILD_GL
 	GBAGLContext* glBackend;
 #endif
-#ifndef _WIN32
+#if !defined(_WIN32) || defined(USE_EPOXY)
 	GBAGLES2Context* gl2Backend;
 #endif
 
-#ifndef _WIN32
+#if !defined(_WIN32) || defined(USE_EPOXY)
 	if (glVersion & QGLFormat::OpenGL_Version_3_0) {
 		gl2Backend = new GBAGLES2Context;
 		GBAGLES2ContextCreate(gl2Backend);
@@ -223,6 +226,9 @@ void PainterGL::filter(bool filter) {
 
 void PainterGL::start() {
 	m_gl->makeCurrent();
+#if defined(_WIN32) && defined(USE_EPOXY)
+	epoxy_handle_external_wglMakeCurrent();
+#endif
 	m_backend->init(m_backend, reinterpret_cast<WHandle>(m_gl->winId()));
 	m_gl->doneCurrent();
 	m_active = true;
@@ -257,6 +263,9 @@ void PainterGL::forceDraw() {
 void PainterGL::stop() {
 	m_active = false;
 	m_gl->makeCurrent();
+#if defined(_WIN32) && defined(USE_EPOXY)
+	epoxy_handle_external_wglMakeCurrent();
+#endif
 	dequeueAll();
 	m_backend->clear(m_backend);
 	m_backend->swap(m_backend);

src/platform/qt/DisplayGL.h

@@ -8,6 +8,11 @@
 
 #include "Display.h"
 
+#ifdef USE_EPOXY
+#include <epoxy/gl.h>
+#include <epoxy/wgl.h>
+#endif
+
 #include <QGLWidget>
 #include <QList>
 #include <QMouseEvent>

src/platform/video-backend.h

@@ -9,6 +9,7 @@
 #include "util/common.h"
 
 #ifdef _WIN32
+#include <windows.h>
 typedef HWND WHandle;
 #else
 typedef void* WHandle;